Australia hit a renewable energy milestone early in October when solar power provided 100% of South Australia’s energy needs for a whole hour.

Mild temperatures and cloudless skies contributed to ideal generation conditions in South Australia on 11 October. Solar power from the state’s 288,000 rooftop systems provided 992 MW and large-scale solar provided 313MW to power the entire state. Rooftop solar is installed on one-in-three homes in South Australia, with 2,500 systems installed monthly in 2020 alone.

Australian Energy Market Operator managing director/CEO, Audrey Zibelman, said the milestone affirmed the world-leading scale and pace of transition underway in Australia’s power system.

“The domination and successful integration of rooftop solar in South Australia foreshadows the rebuilding of jurisdictional power systems in Australia. Never before has a jurisdiction the size of South Australia been completely run by solar power, with consumers’ rooftop solar systems contributing 77%,” Zibelman explained.

The new record followed the previous milestone of 89% of state demand, achieved on September 13 when rooftop solar output reached 900MW for the first time.

AEMO has worked closely with transmission and distribution network service providers to achieve this level of renewable penetration while ensuring the power system remains secure and reliable. “AEMO is also working hard to identify technical solutions to replace power system services, such as inertia, system strength and voltage control, traditionally provided by conventional thermal generation in Australia, to reach higher penetrations of renewable generation,” said Zibelman.

The market operator’s Integrated System Plan forecasts that by 2024, 63% of Australia’s coal generation will need to be replaced with grid-scale renewable energy (26GW) and dispatchable resources (6.19GW). Australia’s distributed energy sources such as rooftop solar PV and residential batteries are expected to double or triple in capacity by 2040.

Solar generation uptake continues to grow exponentially

“South Australia is experiencing a surge in rooftop solar installations. AEMO is forecasting an additional 36,000 new rooftop solar systems in the next 14 months, which will mean that South Australia’s grid will see zero demand as rooftop solar alone will be capable of meeting 100% of demand. This is truly a phenomenon in the global energy landscape,” said Zibelman.

AEMO’s quarterly energy dynamics report did note increased uptake of rooftop solar PV systems coupled with changes in energy use because of the COVID-19 pandemic did reduce electricity demand across Australia’s National Electricity market in the third quarter of 2020. But, as Zibelman pointed out, while electricity demand did reflect the impact of the pandemic with reductions in Victoria, Queensland and New South Wales, residential heating drove an increase in electricity demand in South Australia at the same time.

“The uptake of residential and commercial solar continues at record pace, which was largely responsible for new minimum operational demand records in Victoria, South Australia and Western Australia,” she said.